Simple Solvent Treatment Enabled Improved PEDOT:PSS Performance toward Highly Efficient Binary Organic Solar Cells

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is a key hole-transporting material (HTM) in organic solar cells (OSCs).
• PEDOT:PSS performance is critical for achieving high power conversion efficiency (PCE) but faces challenges from alternative materials and doping strategies.
• Optimizing conductivity, work function, and surface properties of PEDOT:PSS is essential for advancing OSC technology.

Purpose of the Study:

• To develop a simple, dopant-free method for tuning the phase separation of PEDOT:PSS layers.
• To improve charge transport and extraction within OSC devices by modifying PEDOT:PSS.
• To achieve high PCEs in OSCs using engineered PEDOT:PSS layers.

Main Methods:

• A dopant-free approach was employed to control the phase separation of the PEDOT:PSS layer.
• The modified PEDOT:PSS layer was integrated into organic solar cell devices.
• Device performance, including PCE, was evaluated for different OSC architectures.

Main Results:

• Simultaneous high PCEs exceeding 18% for polymer-small-molecule OSCs and 17% for polymer-polymer OSCs were achieved.
• The dopant-free modification significantly improved charge transport and extraction in the devices.
• The method demonstrated an effective strategy for enhancing PEDOT:PSS properties without doping.

Conclusions:

• A simple, dopant-free method effectively tunes PEDOT:PSS phase separation, enhancing OSC performance.
• This approach offers a viable strategy for improving charge transport and extraction in organic solar cells.
• The findings provide valuable insights for optimizing PEDOT:PSS properties and advancing OSC device efficiency.